Gas cylinder

ABSTRACT

A gas cylinder includes a spindle vertically reciprocating along a center shaft, a cylinder installed in the spindle and filled with gas, a piston member sectioning an inside of the cylinder into an upper portion and a lower portion, and a valve member sealing an upper end of the cylinder and controlling flow of the gas filling the inside of the cylinder. The valve member includes a pipe holder sealing an upper end of the cylinder, an open pin inserted in the pipe holder by penetrating the pipe holder, and a sealing member provided at an end portion of the open pin to contact the pipe holder. When the open pin is inclined by a predetermined angle with respect to the center shaft, a gap is formed between the sealing member and the pipe holder so that the flow of the gas is controlled.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a gas cylinder capable of adjusting the height of a chair by pressing an open pin from the side thereof.

2. Description of the Related Art

in general, a gas cylinder used for a chair includes a base tube and a gas spindle. As a spindle of the gas cylinder is moved up and down, the height of a chair seat is adjusted.

FIG. 1 is a cross-sectional view illustrating the structure of a conventional gas cylinder 1. Referring to FIG. 1, the conventional gas cylinder 1 includes a spindle 13 connected to a lower end of a chair seat (not shown), a base tube 11 supporting the spindle 13, and a tube guide 12 inserted between the base tube 11 and the spindle 13 and preventing the spindle from being inclined left and right when the spindle 13 is moved up and down.

In detail, the gas cylinder 10 includes a piston 23 vertically reciprocating in the spindle 13, a piston rod 22 on which the piston 23 is installed, and a cylinder 16 inserted in the inner circumferential surface of the spindle 13 and surface contacting an O-ring (not shown) installed on an outer circumferential surface of the piston 23. The cylinder 16 is divided by the piston 23 into two parts, that is, an upper chamber 20 and a lower chamber 21.

Also, the gas cylinder 10 further includes a gas sealing portion 24 sealing a lower end portion of the cylinder 16, a pipe holder 17 sealing an upper end portion of the cylinder 13, an opening/closing pin 15 inserted in the pipe holder 17 by penetrating the center portion of the pipe holder 17, and an open pin 14 adjusting the opening/closing of the opening/closing pin 15 by a reciprocation motion.

In detail, an orifice 18 through which gas passes is formed at a side of the pipe holder 17. The orifice 18 is opened/closed by the opening/closing pin 15. a gas passage 19 through which the gas exhausted through the orifice 18 flows is formed between the cylinder 16 and the spindle 13.

The function of the conventional gas cylinder 10 configured as above will be described with an example of a user sitting on a chair (not shown). First, when the user sits on the chair and moves an operation lever (not shown) connected to the open pin 14 up or down, the open pin 14 is pressed. When the open pin 14 is pressed downward, the opening/closing pin 15 descends. As the opening/closing pin 15 descends, the gas stored in the upper chamber 20 flows toward the orifice 18 along the side surface of the opening/closing pin 15. The gas flows toward the lower chamber 21 along the gas passage 19. Then, the volume of the lower chamber 21 increases compared to the volume of the upper chamber 20 so that the spindle 13 descends. When the user removed the force applied to the operation lever, the gas flows no longer. Thus, the chair is fixed at a height that the user desires.

In the conventional gas cylinder 10, the height of the chair can be adjusted only when the open pin 14 is pressed from top to bottom. However, since the gas cylinder 10 is generally arranged in the lower portion of the chair, it is not easy for the user to press the open pin 14 from top to bottom.

SUMMARY OF THE INVENTION

To solve the above and/or other problems, the present invention provides a gas cylinder capable of adjusting the height of a chair by pressing an open pin from the side thereof.

According to an aspect of the present invention, a gas cylinder includes a spindle vertically reciprocating along a center shaft, a cylinder installed in the spindle and filled with gas, a piston member sectioning an inside of the cylinder into an upper portion and a lower portion, and a valve member sealing an upper end of the cylinder and controlling flow of the gas filling the inside of the cylinder, wherein the valve member comprises a pipe holder sealing an upper end of the cylinder, an open pin inserted in the pipe holder by penetrating the pipe holder, and a sealing member provided at an end portion of the open pin to contact the pipe holder, and wherein, when the open pin is inclined by a predetermined angle with respect to the center shaft, a gap is formed between the sealing member and the pipe holder, thus controlling the flow of the gas.

When the open pin is pressed by an external force, the open pin may be inclined by a predetermined angle with respect to the center shaft at a contact point between the sealing member and the pipe holder, thus forming the gap between the sealing member and the pipe holder.

When the pipe holder and the sealing member closely contact each other, the flow of the gas may be stopped and, when the pipe holder and the sealing member are separated from each other, the gap may be open to make the gas flow through the gap.

The pipe holder may further include a washer arranged in the pipe holder and the washer and the sealing member may contact each other.

The valve member may further include a packing member encompassing the sealing member.

A hollow portion in which the open pin may be inserted by penetrating the hollow portion is formed in the pipe holder and the inner diameter of the hollow portion may be larger than the outer diameter of the open pin.

An O-ring may be interposed between the pipe holder and the open pin.

The diameter of the sealing member may be large than that of the hollow portion, thus the sealing member covering the hollow portion.

When the open pin is pressed in the axial direction along the center shaft, the sealing member and the pipe holder may be separated from each other, thus controlling the flow of the gas.

The pipe holder may include an inner holder and a washer which are arranged in the pipe holder, and the inner holder and the washer may be formed of materials different from each other.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a cross-sectional view illustrating the structure of a conventional gas cylinder;

FIG. 2 is a cross-sectional view illustrating the structure of a gas cylinder according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating the structure of a valve member of the gas cylinder of FIG. 2;

FIG. 4 is a magnified cross-sectional view of a portion IV of FIG. 3; and

FIG. 5 is a cross-sectional view illustrating the structure of a gas cylinder according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The attached drawings for illustrating exemplary embodiments of the present invention are referred to in order to gain a sufficient understanding of the present invention, the merits thereof, and the objectives accomplished by the implementation of the present invention. Hereinafter, the present invention will be described in detail by explaining exemplary embodiments of the invention with reference to the attached drawings. Like reference numerals in the drawings denote like elements.

FIG. 2 is a cross-sectional view illustrating the structure of a gas cylinder 100 according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating the structure of a valve member 160 of the gas cylinder 100 of FIG. 2. FIG. 4 is a magnified cross-sectional view of a portion IV of FIG. 3.

Referring to FIGS. 2-4, the gas cylinder 100 according to the present embodiment includes a base tube 110, a spindle guide 120, a spindle 130, a cylinder 140, a piston member 150, and the valve member 160. The based tube 110 forms a main body of the gas cylinder 100. The spindle 130 is inserted in the base tube 110 and vertically reciprocates in the base tube 110. The spindle guide 120 is interposed between the base tube 110 and the spindle 130 to support the spindle 130.

The constituent elements related to the vertical reciprocation of the spindle 130 are described in detail. The piston member 150 includes a piston rod 151 fixedly inserted in the base tube 110 and a piston 152 installed at an upper end portion of the piston rod 151. The cylinder 140 is installed in the inner circumferential surface of the spindle 130 and makes a surface contact with the outer circumferential surface of the piston 152. A gas sealing portion 170 is formed at a lower end portion of the cylinder 140 to prevent gas leakage from a lower portion of the cylinder 140. The gas sealing portion 170 includes a gas sealing and a flange. The pressure in the cylinder 140 is maintained at a constant pressure by the gas sealing portion 170.

In detail, the cylinder 140 forms a gas chamber 141 having a predetermined length by the valve member 160 and the gas sealing portion 170. The gas chamber 141 is filled with gas such as nitrogen. The gas chamber 141 is divided into two parts of an upper chamber 141 a and a lower chamber 141 b by the piston 152. The reciprocation of the spindle 130 changes the volumes of the upper and lower chambers 141 a and 141 b.

The upper and lower chambers 141 a and 141 b are maintained at a pressure higher than the atmospheric pressure. A gas passage 135 through which the gas flows between the upper and lower chambers 141 a and 141 b is formed between the cylinder 140 and the spindle 130.

A lower end portion of the piston rod 151 is fixed to a lower end portion of the base tube 110. In detail, a lower side end of the piston rod 151 is fixed to and supported by a fixing place 175 installed at the lower end portion of the base tube 110. A fixing pin 177 is coupled to the lower end portion of the piston rod 151 to prevent the piston rod 151 from being detached from the fixing plate 175. A washer 176 is inserted between the fixing plate 175 and the fixing pin 177 to prevent the fixing plate 175 from being damaged by directly contacting the fixing pin 177.

Also, a bearing 172 is accommodated on an upper side portion of the fixing plate 175. A buffer member 178 is accommodated on an upper portion of the bearing 172. In detail, the bearing 172 includes a ball bearing 174 including a plurality of bearing balls and a bearing supporter 173 formed on upper and lower side portions of the ball bearing 174. The buffer member 178 accommodating in an upper end portion of the bearing 172 buffers shock generated when the spindle 130 arrives at the lowest position at which the lower portion of the spindle 130 collides against the bearing 172.

The valve member 160 sealing the upper portion of the cylinder 140 and controlling the flow of the gas is formed in the upper end portion of the cylinder 140. Referring to FIG. 3, the valve member 160 includes an open pin 161, a sealing member 162, a pipe holder 163, an orifice 164, a packing member 165, an inner holder 167, and a washer 166.

The pipe holder 163 is arranged above the cylinder 140 to seal the upper portion of the cylinder 140. The inner holder 167 and the washer 166 are arranged in the pipe holder 163. Hollow portions 163 a, 166 a, and 167 a, in which the open pin 161 is inserted, are formed at the center portions of the pipe holder 163, the washer 166, and the inner holder 167, respectively. Although the pipe holder 163, the washer 166, and the inner holder 167 are illustrated as separate members in the drawings, the technical concept of the present invention is not limited thereto and the pipe holder 163, the washer 166, and the inner holder 167 may be integrally formed together.

Also, the washer 166 and the inner holder 167 are illustrated as separate members in the drawings, the technical concept of the present invention is not limited thereto and the washer 166 and the inner holder 167 may be integrally formed together. However, since the inner holder 167 may be formed of a synthetic resin material considering a possibility of damage to an O-ring 168, and the washer 166 may be formed of a metal material considering a close contact force to the packing member 165, the washer 166 and the inner holder 167 are preferably formed as separated members.

The orifice 164 is formed in the pipe holder 163 and connected to the gas passage 135 so that the gas filling the inside of the cylinder 140 may flow therethrough.

The open pin 161 is installed in the upper portion of the spindle 130 to protrude a predetermined height from the upper surface of the spindle 130. In detail, the open pin 161 penetrates the hollow portions 163 a, 166 a, and 167 a of the pipe holder 163, the inner holder 167, and the washer 167 to exhaust the gas in the cylinder 140. A large diametric portion 161 a of the opening pin 161 inserted in the pipe holder 163 may have a diameter slightly larger than that of the other portion of the opening pin 161. The diameter of the large diametric portion 161 a of the open pin 161 may be slightly smaller than the inner diameter of the hollow portion 163 a of the pipe holder 163. Thus, the open pin 161 may be slightly moved to the left and right. Also, the O-ring 168 may be further provided in the hollow portion 163 a of the pipe holder 163. That is, the O-ring 168 is arranged in a portion where the large diametric portion 161 a of the open pin 161 contacts the hollow portion 163 a of the pipe holder 163. Accordingly, the O-ring 168 normally fixes the position of the open pin 161 to prevent the open pin 161 from being moved to the left and right with respect to the pipe holder 163. Simultaneously, when a pressure is externally applied to the open pin 161, for example, a pressure indicated by an arrow F1 of FIG. 3 is applied, the O-ring 168 is slightly elastically deformed so that the open pin 161 may be inclined by a predetermined angle.

The sealing member 162 is formed at an end portion of the open pin 161. The sealing member 162 has a substantially circular disc shape like a coin and arranged to contact the washer 166. The diameter of the sealing member 162 is larger than that of the hollow portion 166 a of the washer 166. When the sealing member 162 closely contacts the washer 166, the sealing member 162 completely separates the hollow portion 166 a of the washer 166 from the upper chamber 141 a, thus preventing the flow of gas. In other words, the flow of gas is controlled by the contact and separation between the sealing member 162 and the washer 166.

The packing member 165 may be further provided in the sealing member 162. In detail, the packing member 165 is formed of an elastic material exhibiting a superior close contact characteristic, such as rubber, to encompass the sealing member 162. Thus, the packing member 165 plays an auxiliary role in making the sealing member 162 further closely contact the washer 166.

In the operation of a height adjustment mechanism of the gas cylinder 100 configured as above, when a user sits on a chair, the spindle 130 slightly descends due to the weight of the user. Accordingly, the volume of the upper chamber 141 a decreases so that the pressure of the inside of the cylinder 140 increases. That is, both of the pressure formed in the cylinder 140 before the user sits on the chair and the pressure due to the user's weight apply to the upper chamber 141 a.

Referring to FIGS. 3 and 4, to reduce the height of the chair while the user is sitting on the chair, when the open pin 161 is pressed in a direction perpendicular to a shaft of the open pin 161, that is, in a direction F1 of FIG. 3, the open pin 161 is inclined by a predetermined angle. In detail, when the open pin 161 is pressed in the direction F1 of FIG. 3, the open pin 161 is inclined with respect to a first contact point CP1 between the sealing member 162 and the washer 166. Thus, as the sealing member 162 and the washer 166 are separated from each other, a gap g is formed at a second contact point CP2. That is, in the present embodiment, the gap g is formed according to the leverage effect. Thus, the elastic deformation of the sealing member 162 or the washer 166 is not necessarily required. However, as described above, the packing member 165 that is formed of an elastic material exhibiting a superior close contact characteristic, such as rubber, may be further formed to encompass the sealing member 162.

When the gap g is formed, the gas stored in the upper chamber 141 a passes through the gap g and moves toward the orifice 164. The gas moved toward the orifice 164 is moved to the lower chamber 141 b along the gas passage 135. Then, the volume of the lower chamber 141 b increases to be larger than that of the upper chamber 141 a so that the spindle 130 descends. Finally, when the user removes the force applied to an operation lever (not shown), a gas pressure is applied to the sealing member 162 in a direction from bottom to top so that the sealing member 162 is returned to the original position and closely coupled to the washer 166, thus sealing the hollow portions 166 a and 167 a. Accordingly, the gas does not flow any longer so that the chair is fixed at a desired height.

Although FIG. 3 illustrates that the force is applied in the direction perpendicular to the shaft of the open pin 161, that is, in the direction F1, the technical concept of the present invention is not limited thereto so that, even when the open pin 161 is pressed in any direction, the open pin 161 is inclined so that the height of a chair may be adjusted. In the gas cylinder 100 according to the present embodiment configured as above, since the height can be adjusted by pressing the open pin 161 from the side thereof, user convenience may be improved and the manipulation of a chair becomes easier.

Another height adjustment mechanism of the gas cylinder 100 configured as above is described below with reference to FIG. 5. FIG. 5 is a cross-sectional view illustrating the structure of a gas cylinder according to another embodiment of the present invention. Referring to FIG. 5, to reduce the height of a chair while a user is sitting on the chair, the open pin 161 is pressed in an axial direction along the shaft of the open pin 161, that is, in a direction F2 of FIG. 5. When the open pin 161 descends, the gas stored in the upper chamber 141 a flows toward the orifice 164 along the side surface of the open pin 161. The gas flows toward the orifice 164 is moved to the lower chamber 141 b along the gas passage 135. Then, the volume of the lower chamber 141 b is increased to be larger than that of the upper chamber 141 a so that the spindle 130 may descend. Finally, when the user removed the force applied to the operation lever, the gas does not flow any longer. Thus, the chair is fixed at a desired height.

That is, as described above, not only when the open pin 161 is pressed in the direction perpendicular to the shaft of the open pin 161, that is, in the direction F1 of FIG. 3, but also when the open pin 161 is pressed in the axial direction of the open pin 161, that is, in the direction F2 of FIG. 5, the height of a chair can be adjusted so that user convenience may be further improved.

As described above, in the gas cylinder according to the present invention configured as above, since the height of the gas cylinder can be adjusted by pressing the open pin by the side thereof, user convenience is improved so that a chair may be easily manipulated.

While this invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 

1. A gas cylinder for a chair vertically reciprocating along a center shaft, the gas cylinder formed to enable vertical reciprocation of the chair when an open pin controlling a flow of gas filling an inside of the gas cylinder is pressed in any of an axial direction along the center shaft and a direction substantially perpendicular to the center shaft.
 2. The gas cylinder of claim 1, comprising: a cylinder filled with gas; and a pipe holder sealing an end portion of the cylinder, wherein the vertical reciprocation of the chair is controlled according to whether the open pin and the pipe holder are closely contacted or not.
 3. The gas cylinder of claim 2, wherein, when the open pin is pressed in the axial direction of the center shaft, the open pin and the pipe holder are separated from each other.
 4. The gas cylinder of claim 2, wherein, when the open pin is pressed in the direction substantially perpendicular to the center shaft, the open pin is inclined with respect to the pipe holder at a contact point where the open pin contacts the pipe holder.
 5. A gas cylinder comprising: a spindle vertically reciprocating along a center shaft; a cylinder installed in the spindle and filled with gas; a piston member sectioning an inside of the cylinder into an upper portion and a lower portion; and a valve member sealing an upper end of the cylinder and controlling flow of the gas filling the inside of the cylinder, wherein the valve member comprises: a pipe holder sealing an upper end of the cylinder; an open pin inserted in the pipe holder by penetrating the pipe holder; and a sealing member provided at an end portion of the open pin to contact the pipe holder, and wherein, when the open pin is inclined by a predetermined angle with respect to the center shaft, a gap is formed between the sealing member and the pipe holder, thus controlling the flow of the gas.
 6. The gas cylinder of claim 5, wherein, when the open pin is pressed by an external force, the open pin is inclined by a predetermined angle with respect to the center shaft at a contact point between the sealing member and the pipe holder, thus forming the gap between the sealing member and the pipe holder.
 7. The gas cylinder of claim 5, wherein, when the pipe holder and the sealing member closely contact each other, the flow of the gas is stopped and, when the pipe holder and the sealing member are separated from each other, the gap is open to make the gas flow through the gap.
 8. The gas cylinder of claim 5, wherein the pipe holder further comprises a washer arranged in the pipe holder and the washer and the sealing member contact each other.
 9. The gas cylinder of claim 5, wherein the valve member further comprises a packing member encompassing the sealing member.
 10. The gas cylinder of claim 5, wherein a hollow portion in which the open pin is inserted by penetrating the hollow portion is formed in the pipe holder and the inner diameter of the hollow portion is larger than the outer diameter of the open pin.
 11. The gas cylinder of claim 10, wherein an O-ring is interposed between the pipe holder and the open pin.
 12. The gas cylinder of claim 10, wherein the diameter of the sealing member is large than that of the hollow portion, thus the sealing member covering the hollow portion.
 13. The gas cylinder of claim 5, wherein, when the open pin is pressed in the axial direction along the center shaft, the sealing member and the pipe holder are separated from each other, thus controlling the flow of the gas.
 14. The gas cylinder of claim 5, wherein the pipe holder comprises an inner holder and a washer which are arranged in the pipe holder, and the inner holder and the washer are formed of materials different from each other.
 15. The gas cylinder of claim 14, wherein the inner holder is formed of a synthetic resin based material.
 16. The gas cylinder of claim 14, wherein the washer is formed of a metal based material and the washer and the sealing member contact each other.
 17. A gas cylinder for a chair, the gas cylinder comprising: a cylinder; a pipe holder arranged in an upper portion of the cylinder; an open pin inserted in the pipe holder by penetrating the pipe holder; and a sealing member formed at an end portion of the open pin, wherein the open pin and the sealing member are capable of pivoting with respect to the pipe holder.
 18. The gas cylinder of claim 17, wherein, when the open pin and the sealing member pivot with respect to the pipe holder, gas flows between the sealing member and the pipe holder.
 19. The gas cylinder of claim 17, wherein the open pin pivots with respect to a contact point between the sealing member and the pipe holder.
 20. The gas cylinder of claim 17, wherein a hollow portion in which the open pin is inserted by penetrating the hollow portion is formed in the pipe holder and the sealing member covers an end portion of the hollow portion. 